NEW DELHI (AP) — Indian conglomerate Reliance Industries says it’s selling a 20% stake in its oil and chemicals business to Saudi oil giant Aramco, calling the deal India’s largest foreign direct investment.

The Press Trust of India News Agency says the deal is worth $15 billion.

Reliance Industries Chairman Mukesh Ambani says Aramco will also supply Reliance’s Jamnagar refineries with 700,000 barrels of oil a day on a long-term basis. The refining complex has a capacity to process 1.4 million barrels per day.

Ambani said Monday that Reliance will also sell around half of its fuel retail business to global oil major BP for 70 billion rupees ($1 billion).

Last week, Reliance said it was forming a fuel retailing joint venture with BP in which Reliance would own a 51% stake.